The watchdog for European citizens has said people have a right to know what the UK's Brexit negotiators are tabling.

As the second round of talks on the split got underway in Brussels, Emily O'Reilly said she had yet to see options for a so-called soft border between the Republic of Ireland and Northern Ireland.

The European Ombudsman also warned about "mixed signals" and "uncontrolled leaks" from Prime Minister Theresa May's Cabinet.

Ms O'Reilly told parliamentarians from Ireland, Northern Ireland, Scotland, Wales, the Isle of Man, Guernsey and Jersey that voters need to be given as much neutral information as possible and what the consequences might be.

"Irrespective of your views on Brexit, the people at the very least deserve honesty and honesty at every stage of this process," she said.

Ms O'Reilly said it is inconceivable that leaks will not happen but she said it would be better to publish as many documents as possible to control the spin.

At a meeting of the British-Irish Parliamentary Assembly in Kilkenny, the Ombudsman gave an impassioned defence of the work of the European Union, from women's rights to environmental reform.

She praised the attitude of Europe's chief negotiator Michael Barnier towards transparency in the talks and called for the greatest possible openness.

"While much of Brexit is highly technical and bureaucratic, it is still being played out on a political stage and if greater transparency is seen to be useful to one side then greater transparency we shall have," Ms O'Reilly said.

"It will not have gone unnoticed in Brussels that - certainly before the general election - the British Government was urging secrecy around the talks process and counselling in very strong terms against leaks.

"In a divided, divisive and febrile atmosphere, uncontrolled leaks risk undermining both the negotiating team and the Government itself."

Ms O'Reilly described the negotiations as the greatest "chess game of our lives" and she said people have a "right to know".

The former journalist, who headed up the ombudsman's office in Ireland before moving to the European role in 2013, also noted the influence law firms and consultancies were trying to exert on the Brexit talks.

"The EU chief negotiator Michel Barnier is being transparent in relation to his meetings but influence is attempted to be peddled at all levels and in every member state with a stake in the outcome of these negotiations," she said.

"The transposition of EU laws and regulations into the UK legal framework is an area also ripe for lobbyists and while that of course is none of my business, I expect that this is where UK politicians will be keeping a close eye."

Ms O'Reilly also told parliamentarians that one of the first investigations she launched in the public interest concerned the transparency of negotiations between the EU and the United States in the Transatlantic Trade and Investment Partnership (TTip) deal.

Britain's ambassador to Ireland Robin Barnett addressed the issue of the border between the Republic and Northern Ireland and said Mrs May's Government "gets" that north-south movement and trade i s an "essential part of daily life".

"My point is that, notwithstanding the inevitable challenges ahead, our relationship need not be defined by Brexit," he said.

"I realise that some might consider that statement to be naive but I genuinely believe that there are opportunities to bolster this already special relationship."